Back in 2008, the original American expandable booster seat was created right here at Diono. Fast forward to today as we welcome the next evolution in a long-standing legacy. We’ve taken the award-winning Monterey and painstakingly engineered 15 upgrades to create the Monterey® 4DXT. From the remodeled headrest, enhanced fabric covering, contoured seat base and breathable exo-shell panels, we’ve considered every last detail to create a contemporary new look.